Technical Field
The present disclosure generally relates to providing over-voltage protection in a proactively operational way.
Description of the Related Art
Power converters alter electrical energy from one form to another. For example, some power converters transform AC power signals to DC power signals, and vice versa, whereas some power converters alter the frequency and/or voltage of an input power signal. A DC/DC converter converts an input DC voltage to a different output DC voltage. Such converters typically include a transformer that is electrically coupled via a switching circuit between a voltage source and a load. Such converters are also typically controlled by a closed-loop feedback system that is designed such that the converter maintains the output voltage within a pre-defined and highly precise range. If the feedback loop fails, though, the output voltage may increase uncontrollably until the converter or the load, or both, is damaged.
Designers incorporate over-voltage protection into power converter system to prevent a feedback loop failure from further damaging the transformer circuit or the load. Over voltage protection may be incorporated into other systems in which a feedback loop is used under normal operation to prevent the output voltage from exceeding a certain level. Traditional systems and methods for providing over-voltage protection include implementations that use a latching scheme or a non-latching scheme. In a latching scheme, the power converter may be shut-down when an over-voltage situation occurs and remain shut-down until restarted, for example, by cycling the input power. In a non-latching scheme, the power converter may be power cycled in order to restart when an over-voltage situation occurs. If power cycling does not correct the over-voltage situation, though, the power converter may continue to operate in a faulty power cycling, or “hiccup,” mode that stresses both the power converter and its load, thus compromising the circuitry's integrity and potentially reducing its useful lifetime. Moreover, traditional systems set a threshold value of 130% or more of the nominal operating voltage before the over-voltage protection circuit is engaged to provide the output voltage. A high voltage threshold is necessary to prevent false triggering of the over-voltage protection circuitry, but it also results in stressing and possibly damaging the converter and the load circuitry by applying an excessively high voltage. Accordingly, these traditional methods for providing over-voltage protection result in an output voltage that either is not usable by the load, or if used, may result in damage to the converter or to the load.